The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper focuses on the detection and quantification of three types of noise, analog-to-digital converter (ADC) clipping, quantization noise, and amplifier saturation, in surface electromyography (sEMG) without prior information regarding the sEMG setup. ADC clipping can be detected by searching for consecutive minimum and maximum values in a signal. Quantization noise can be expressed as a signal-to-quantization...
In recent times, digital watermarking has become one of the advanced technologies to protect images from illicit manipulations. A non-blind robust Discrete Wavelet Transform domain watermarking approach for images is introduced in this paper. Based on the parent-child relationship between wavelet coefficients, the Set Partitioning in Hierarchical Trees (SPIHT) algorithm is applied on the transformed...
This work presents a simple approach to the correction of absolute gain errors in a tunable continuous-time bandpass Delta-Sigma modulator based on a Leslie-Singh architecture. The calibration is performed in the digital domain using the employed hardware. Thus, no additional analog circuitry overhead is added to the system. By tuning the center frequency of the analog resonator for correction, matching...
A mismatch-tolerant current-mode Sigma Delta (ΣΔ) Digital to Analog Converter (DAC) is presented here. The current mode DAC is designed such that the outputs of any two adjacent current elements can be progressively brought out for separate ΣΔ operation. This increases the DAC range even as the ΣΔ step size and range are kept small to minimize ΣΔ switching noise. Mismatch between DAC current elements...
This paper presents an in-depth analysis of the generation of tones in the output spectra of vector-quantizer (VQ) based multibit mismatch-shaped ΔΣ digital-to-analog converters (DACs). Building upon the analysis, a simple yet elegant method of adding dither to remove tones from the output spectra is presented. It achieves a better mismatch shaping performance with a low hardware cost compared to...
A sensor network's motes observe the environment, make estimates based on observations with spatially correlated noise sources, and then send/relay these estimates to a Cluster-Head (CH). A novel scheme based on dithered quantization and channel compensation is used to ensure that each mote's local estimate received by the CH is unbiased. Based on an upper bound of the noise covariance matrix, the...
Randomized (dithered) quantization is a method capable of achieving white reconstruction error independent of the source. Dithered quantizers have traditionally been considered within their natural setting of uniform quantization. In this paper we extend conventional dithered quantization to nonuniform quantization, via a subterfage: dithering is performed in the companded domain. Closed form necessary...
The paper deals with modular design of constrained disturbance observer (DO) based PI control with different filtering properties. After treating possible effects of control constraints completing deeper analysis of the core structure of the P controller with different types of additional dynamics approximations [1], it will be expanded by considering structures of constrained PI1 controllers, in...
In this paper, a lossy data compression for a sparse histogram image signal is proposed. It is extended from an existing lossless coding which is based on a lossless histogram packing and a lossless coding. We introduce a lossy mapping, which has less computational load than the rate-distortion optimized Lloyd-Max quantization, and combine it with a lossless coding. It was confirmed that the proposed...
We consider the problem of distributed average consensus in a sensor network where sensors exchange quantized information with their neighbors. In particular, we exploit the increasing correlation between the exchanged values throughout the iterations of the consensus algorithm in order to design a novel quantization scheme, particularly efficient at low bit rates. We implement a low complexity, uniform...
An important application of Active Noise Control (ANC) is to reduce noise produced by machinery in modern living places. We present an ANC system that is designed to cancel narrowband noise generated from the compressor of an HVAC (Heating, Ventilation, and Air-Conditioning) system in real time. To achieve cost effectiveness of the system, we propose a single-channel Feedback ANC implementation, which...
Time-to-digital converters (TDCs) were historically used in laser range-finding, automatic test equipment, and timing jitter measurements, but recent developments in the design of high-resolution TDCs have paved the way for mostly digital implementation of PLLs and ADCs. Among the state-of-the-art TDCs, a flash TDC is the simplest, but its resolution is technology-limited by the minimum gate delay...
We propose a denoising technique for multiple exposure image integration. In our method, noise removal is achieved by the wavelet-shrinkage for multiple exposures, and a novel weighting scheme for the integration. A weighted image is converted to the low and the high frequency elements by the shift invariant wavelet transform, and the wavelet coefficient in the high frequencies are decreased by thresholding...
In quantized control system, the control system performance is degraded by different kinds of noise, but also the noise can make the encoder/decoder pairs overflow. In the latter case, we cannot get the effective information of the state. In this paper, the noise flag method which classifies the different kinds of noise is proposed to make the bound less conservative. The new method solves the problem...
In this paper, we endeavor for predicting the performance of quantized compressive sensing under the use of sparse reconstruction estimators. We assume that a high rate vector quantizer is used to encode the noisy compressive sensing measurement vector. Exploiting a block sparse source model, we use Gaussian mixture density for modeling the distribution of the source. This allows us to formulate an...
The use of fixed point arithmetic for digital signal processing applications has several benefits in terms of cost, energy consumption and time to market. The existing analytical approaches for evaluating fixed-point systems performance are not able to evaluate the error caused by quantization noise in the case of un-smooth operators such as decision operators and especially when the quantization...
The signal processing and control algorithms are widely based on sum-of-products evaluation. In fixed-point arithmetic, the roundoff errors and coefficient quantization may have an important effect on the application's performance and characteristics. As part of a global methodology on optimal fixed-point implementation of filters/controllers, this paper formalizes the various implementation schemes...
To satisfy cost constraints, application implementation in embedded systems requires fixed point arithmetic. Thus, the application defined in floating point arithmetic must be converted into a fixed-point specification. This conversion requires accuracy evaluation to ensure algorithm integrity. Indeed, fixed-point arithmetic generates quantization noises due to the elimination of some bits during...
Gender is one of the most important demographic attributes of human beings, and recently automatic face-based gender classification has received increasing attentions due to its wide potential in many useful applications. To address such an issue, in this paper, we propose a novel variant of Local Binary Patterns (LBP), namely Local Circular Patterns (LCP). LCP makes use of clustering-based quantization...
In this paper the Coding Efficiency in multi-bit delta-sigma based transmitters has been improved significantly by only adjusting the quantizer's threshold values. To achieve this, the transmitter's linearity should be compromised. Usually the space between thresholds in a quantizer of a multi-bit delta-sigma modulator is uniform which not the optimum choice is for Coding Efficiency. For an LTE signal...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.